The mortality rates in exposed and unexposed areas were compared. Exposure to radio transmitter was defined as living within 2 km of an AM radio transmitter with at least 100 kW power output. Cancer mortality rates were calculated for the ten exposed regions including AM radio transmitters over 100 kW and forty unexposed regions.
|Reference group 1||distance of residence to radio transmitter: < 2 km|
|Group 2||distance of residence to radio transmitter: ≥ 2 km|
The mortality rates for all cancers were 113.07 per 100,000 persons in the exposed group and 87.32 per 100,000 persons in the control group. All cancer mortality in the population living within 2 km distance from an AM radio broadcasting transmitter with a power output of more than 100 kW was 1.29 times higher than in the population living in a distance of more than 2 km (CI 1.12-1.49). Leukemia mortality was significantly higher in the exposed population among young adults: 2.29-times higher in the 0-14 years age group (CI 1.05-5.98) and 2.44-times higher in the 15-29 years age group (CI 1.07-5.24).
The authors concluded that higher mortality rate for all cancers and leukemia in young age groups were observed in the area near the AM radio broadcasting stations. However these findings prove no causal link.
The exposure was not assessed for the individual but for the residents of a defined area.